摘要:设计并讨论了一种高单位增益带宽CMOS全差分运算放大器。由于折叠共源共栅结构电路具有相对高的单位增益带宽以及开关电容共模反馈电路稳定性好、对运放频率特性影响小等优点,故设计的放大器采用了折叠共源共栅结构以及开关电容共模反馈电路技术,并达到了高单位增益带宽的设计目的。基于TSMC0.25μmCMOS工艺,仿真结果表明,在2.5V的单电源电压下,运算放大器的直流开环增益为70dB,单位增益带宽为500MHz。
This paper designs and discusses a high unity- gain bandwidth CMOS fully differential operational amplifier. Because of these merits of the high unity - gain bandwidth of folded - cascode and switched - capacitor CMFB' s good stability, little effect on frequency characteristic of operational amplifier. This operational amplifier uses the techniques of folded - cascode and switched - capacitor CMFB circuits to obtain a high unity - gain bandwidth. The operational amplifier is designed in TSMC 0. 25μm CMOS process with 2.5 V power supply and the frequency response shows that a DC open - loop gain of 70dB and a 500 MHz unity - gain bandwidth are achieved.